As has been said multiple times now, this is not Scrivener’s cursor. It is the new macOS cursor, like it or hate it, that is what your Mac is now going to start looking like as more and more programs get fixed to use it.
If you do not like it to the degree that you will stop using Scrivener (!), then downgrade your Mac back to 13, and hang on to it as long as you can. Hopefully by the time you can’t use that anymore because your hardware breaks or Apple stops supporting it and nobody is making software for it anymore, they will have come to their senses and either made this optional for iOS users that think it’s neat, or they will hopefully add controls so developers can go back to making the cursor look how they think it should in their software.
Until then, asking us to change it is like asking us to change the spell check engine or how the title bar on the window works. Please send your feedback to Apple. They are not hearing you, here.
I am closing this thread for now. If you scrolled to this point looking to file a bug about the cursor, it’s probably best to start a new thread on it anyway, as the bug this thread was about has been resolved. Thanks!